[mythtv-users] HD3000 and High-Def

[Cory Papenfuss]

> I could be wrong here, but I am fairly sure that your use of SD to as an
> alias for VSB is not correct.  SD and HD are both digital formats and not
> analog, the difference being the resolution.  Conventional frame-grabber
> cards don't and can't do SD. They do as you correctly said earlier,
> receive and digitise a 6MHz wide VSB signal.  The video they output may be
> of the same resolution as SD, but thats really just coincidental.
>
 	Perhaps forgetting what I *said*, but instead referring to what I 
*meant* (heh... ), I suppose I can almost agree with you.  If there is a 
standard decreeing that SDTV is the 480i version of digital TV, then feel 
free to point it out.  I was under the impression that "SDTV" meant any 
video signal that has an interlaced 480 scanlines.  That is in contrast to 
EDTV which is 480p, and HDTV which (depending upon whom you ask) is 720p, 
1080i, or 1080p.

 	I would argue that frame-grabber cards "do" SD... they can convert 
from an analog representation to a digital representation as a 480i 
signal.  If that analog signal came down the RF line, it was a 
VSB-modulated signal.  If it came in the composite or s-vid, it was 
baseband video.

 	It's a symmatic argument.

-Cory

  --

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* Cory Papenfuss                                                        *
* Electrical Engineering candidate Ph.D. graduate student               *
* Virginia Polytechnic Institute and State University                   *
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